Electromagnetic relay

ABSTRACT

AN ELECTROMAGNETIC RELAY ASSEMBLY OF THE PLUNGER TYPE CONSISTING OF SEPARATE ELECTROMAGNETIC AND SWITCH STRUCTURES, WITH A SNAP-ON TYPE BINDING MEMBER MOUNTED ON THE ELECTROMAGNET STRUCTURE AND GRIPPING THE SWITCH STRUCTURE TO HOLD THE TWO TOGETHER IN A SIMPLIFIED MANNER SO THAT THE ELECTROMAGNET PLUNGER BEARS ACCURATELY ON THE MOVABLE ACTUATOR OF THE SWITCH ASSEMBLY. BOTH THE ELECTROMAGNET AND THE SWITCH PORTIONS OF THE UNIT ARE OF CONVENIENTLY SIMPLE CONSTRUCTION FOR EASE OF ASSEMBLY, ELIMINATING THE NEED FOR FASTENING ELEMENTS SUCH AS SCREWS AND THE LIKE. THE ENTIRE ASSEMBLY IS FITTED WITHIN A HOUSING, AND A SEPARATE MOUNTING ELEMENT IS PROVIDED FOR SECURING THE RELAY TO A WALL STRUCTURE.

ELECTROMAGNETIC RELAY 2 Sheets-Sheet 1 Filed March 12, 1969 MW u 4 m 7M0 7 5 Wm INVENTOR I BY ATTORNEY Feb. 2, 1971 s zU NOR" ETAL 3,560,901

ELECTROMAGNETIC RELAY Filed March 12, 1969 Sheets-Sheet 2 .Sl-l/ZU/MHORI/ FU/l/YOSH/ WAD/1 INVENTOR BY W, M f %m ATTORNEY United StatesPatent Ofice- US. Cl. 335-132 9 Claims ABSTRACT OF THE DISCLOSURE Anelectromagnetic relay assembly of the plunger type consisting ofseparate electromagnet and switch structures, with a snap-on typebinding member mounted on the electromagnet structure and gripping theswitch structure to hold the two together in a simplified manner so thatthe electromagnet plunger bears accurately on the movable actuator ofthe switch assembly. Both the electromagnet and the switch portions ofthe unit are of conveniently simple construction for ease of assembly,eliminating the need for fastening elements such as screws and the like.The entire assembly is fitted within a housing, and a separate mountingelement is provided for securing the relay to a wall structure.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to anelectromagnetic relay of the plunger type, that is, the relay in whichthe plunger of the electromagnet controls the opening and closing of theswitch contacts.

This type of electromagnetic relay generally comprises two portions,that is, an electromagnet structure and a switch mechanism, and thesetwo portions must be mechanically combined in such a manner that theplunger of the electromagnet structure may properly control the openingor closing of the contacts of the switch mechanism. In other words, themovement of the plunger must be exactly transferred to the movablecontact member of the switch. If screws or the like are employed toassemble the two portions of the relay, the manual work involved istroublesome and time-consuming. Various devices have been proposed tosolve the problems, but to the best knowledge of the present inventorsthey are all more or less complicated in construction.

Accordingly, it is one object of the invention to provide a new andimproved electromagnetic relay of the plunger type which is easy inassemblage or decomposition of the component parts.

Another object of the invention is to provide such an electromagneticrelay as aforesaid in which the movement of the plunger of theelectromagnet structure can be transferred to the movable contactmembers of the switch mechanism with such stability and exactness as toassure reliable operation of the switch.

Still another object of the invention is to provide such anelectromagnetic relay as aforesaid which can be easily mounted onto ordismount from a suitable supporting member such as a panel of a controlboard.

The invention will best be understood from the following description ofa preferred embodiment thereof with reference to the accompanyingdrawings, wherein:

FIG. 1 is a front elevation, partly broken away, of the relay of theinvention;

FIG. 2 is a side elevation of FIG. 1;

FIG. 3 is a sectional view taken on the line IIIIII of FIG. 1;

Patented Feb. 2, 1971 FIG. 4 is a sectional view taken on the line lV-IVof FIG. 3;

FIG. 5 is an exploded perspective view of the switch mechanism of therelay as shown in FIGS. l-4;

FIG. 6 is a perspective view of a binding member for combining theelectromagnet structure and the switch mechanism of the relay;

FIG. 7 is a front elevation, partly broken away, of the relay as it ismounted on a panel;

FIG. 8 is atop plan view of FIG. 7;

FIG. 9 is a perspective view of the member for mounting the relay ontothe panel;

FIG. 10 is a perspective view of a modified form of the the movableswitch contact member actuating member shown in FIG. 5.

Referring now in detail to the drawings, the electromagnetic relay ofthe invention comprises an electromagnet structure and a switchmechanism generally designated at 10 and 11, respectively, and enclosedin a box-like casing 12 of transparent plastic material in assembledrelation.

The electromagnet structure 10 comprises a spool 13, an electromagneticcoil 14 wound thereon, a generally -shaped yoke .15 formed of magneticmaterial, an end plate 16 of magnetic material to reduce the loss of themagnetic flux, a stationary iron core 17 extending axially of the coil14 and adapted to be pulled toward the core 17 against the resiliency ofa compression spring 18 upon energization of the coil 14. The yoke 15has two pairs of legs 15a and 15b, one pair at each side. The lower endsof each pair of legs are provided with downwardly projecting tongues 20aand 20b, respectively, whose length is equal to the thicknes of the endplate 16. Notches 21a and 21b are formed in each of the opposite ends ofthe plate 16 to receive therein the tongues 20a and 20b of the yoke legs15a and 15b to securely connect the yoke 15 and the plate 16. The spool13 with the coil 14 wound thereon is first combined with the yoke 15with the fixed iron core 17 being inserted into the axial bore of thespool, and the end plate 16 is then connected to the yoke 15 in themanner mentioned just above to securely assemble the parts. Theelectromagnet structure of the relay is thus assembled as a unitindependent of the switch mechanism except for the plunger 19 and thespring 18 to be described later.

The switch mechanism of the relay comprises a base plate 22 provided atopposite ends with a pair of upright side walls 23 and 24, and a pair ofspaced partition walls 25 and 26 extending between the side Walls 23 and24 transversely thereof to divide the space above the base plate 22 intothree chambers 27, 28 and 31. The chamber 27 is defined by one sideportion of each of the side walls 23 and 24 and the partition wall 25;the chamber 28 by the other side portion of each of the side walls 23and 24 and the partition wall 26; and the chamber 31, by the middleportions of the side walls 23 and 24 and the two partition walls 25 and26. The chambers 27 and 28 enclose a set of switch contact members,while through the chamber 31 there pass a pair of lead lines, one ofwhich is shown at 29 in FIG. 2, connecting the coil 14 to a pair ofterminals 102 and 103'.

The partition wall 25 comprises two portions each of which extends fromthe side wall 23, 24 perpendicularly thereof and bends inwardly of thecontact chamber 27 to form a wall portion 32, 33 extending a smalldistance in parallel with the side walls 23 and 24 and terminating in ashort wall portion 34, 35, with a small gap or groove 36 interposedbetween the wall portions 32, 34 and 33, 35. Similarly, the otherpartition wall 26 comprises two portions each of which extends from theside wall 23, 24 perpendicularly thereof and bends inwardly of thechamber 28 to form a wall portion 32', 33 extending a small distance inparallel with the side walls 23 and 24 and terminating in a short Wallportion 34', 35, with a small gap 36 intervening between the wallportions 32, 34, and 33', 35'. The gaps 36 and 36' extend in alignmentwith each other and parallel with the side walls 23 and 24.

A switch contact mechanism is enclosed in each of the chambers 27 and28. In the chamber 27, there are provided two pairs of fixed orstationary contact members 41, 42, 43, 44. As best shown in FIG. 5, thecontact member 41 stands upright alongside the inner surface of the sidewall 23, and a little below the upper edge of the wall 23 the member 41is bent inwardly of the chamber 27 and horizontally extends a suitabledistance to provide an upper contact on the under surface thereof. Thelower end of the contact member 41 projects downwardly through the baseplate 22 to provide a terminal outside the chamber 27 for connection ina circuit. The contact member 42 stands upright alongside the innersurface of the short wall 34 as high as the upper edge thereof, where itis bent toward the member 41 to extend horizontally to provide a lowerstationary contact on the upper surface thereof just below the upperstationary contact. The lower end of the member 42 projects downwardlythrough the base plate 22 to serve as a terminal outside the chamber 27.In a similar manner, the contact members 43 and 44 are so bent andshaped as to provide a pair of upper and lower stationary contactsarranged symmetrically with the above-mentioned pair of stationarycontacts across the wall portions 34 and 35. As will be seen later, theupper contacts serve as a normally open contact and the lower contacts,as a normally closed contact to be opened upon energization of the coil14.

A movable contact member 45 has its one end interposed between the upperand lower stationary contacts provided by the contact members 41 and 42and its opposite end interposed between the upper and lower stationarycontacts provided by the contact members 43 and 4-4. A coil spring 46has its lower end disposed in the groove 36 and its upper end bearing upthe under surface of the middle portion of the movable contact member 45to bias the latter toward the upper stationary contact.

The switch mechanism enclosed in the other contact chamber 28 is of thesame construction as that in the chamber 27 just described above.Therefore, the corresponding component parts of the mechanism in thechamber 28 are designated by the same reference numerals with a addedthereto as those designating the parts of the-switch mechanism in thechamber 27.

The movable contact members 45 and 45' in the two chambers 27 and 28 aresimultaneously moved by a common actuator 51. The actuator is made of asuitable insulating material and loosely inserted in the aligned grooves36 and 36 so as to be vertically slidable therein. The actuator 51 isformed in the middle portion of its upper edge with a notch 52 forreceiving therein the lower end of the plunger 19, and at the oppositesides of its under edge with a pair of notches 53 and 54 for engagementwith the middle portions of the movable contact members 45 and 45',respectively. Normally, the plunger 19 projects downward due to theresiliency of the spring 18, so that the actuator 51 presses the movablecontact members 45 and 45' onto the lower stationary contacts againstthe force of the springs 46 and 46', respectively. When the coil 14 isenergized to pull the plunger 19 upward against the resiliency of thespring 18, the springs 46 and 46 move the movable contact members 45 and45' from the lower stationary contacts into contact with the upperstationary contacts.

To assemble the electromagnet structure and the switch structure 11, abinding member 61 as show in FIG. 6 may advantageously be used. Thebinder 61 is U-shaped and comprises a pair of side wall elements 62 and63 spaced apart and connected by a top wall element 62 is longitudinallyand centrally slotted to form a pair of vertical legs 64 and 65connected at their respective lower ends by a horizontal connectingelement 68. Similarly, the other side wall element 63 comprises a pairof vertical legs 66 and 67 and a horizontal connecting element 69. Onthe other hand, the side walls 23 and 24 of the base plate 22 of theswitch structure are provided on their respective lateral surfaces witha pair of parallel vertical grooves 71, 72 and 73, 74 connected at theirlower ends by a horizontal groove, with a central lug 75, 76 projectinga little from the lateral surface of each side wall 23, 24.

The electromagnet structure 10 is placed on the switch structure 11 withan insulating plate 80 interposed therebetween in such a manner that theplunger 19 is urged by the spring 18 to push down the actuator 51thereby to press the movable contact members 45 and 45' onto theirrespective lower stationary contacts. The two structures 10 and 11 thusassembled are then fitted in between the side wall elements 62 and 63 ofthe binder 61, with a leaf spring 77 interposed between the undersurface of the top wall of the binder 61 and the upper surface of theelectromagnet structure 10 as far as the lower ends of the legs of eachside wall element 62, 63 are fitted into the corresponding grooves ofeach side wall 23, 24 of the switch structure 11, respectively, with theconnecting portion 68, 69 being fitted into the horizontal groove toengage the projecting lug 75, 76 as best shown in FIG. 2. Under thiscondition, the resiliency of the leaf spring 77 tending to urge theelectromagnet structure and the bind ing member 61 in oppositedirections helps ensure the engagement of the horizontal connectingportions 68 and 69 of the side walls 61 and 62 of the binder 61 with theprojecting lugs and 76 of the side walls 23 and 24 of the switchstructure, thereby preventing casual separation of the two assembledstructures 10 and 11.

The relay thus assembled may be enclosed in a casing 12. Near the bottomedges of the opposite side walls of the casing 12 there are provided apair of apertures 81 and 82 into which the laterally projecting lugs 75and 76 on the side walls 23 and 24 of the switch structure engage,respectively, thereby preventing the relay body from slipping out of thecasing 12.

To mount the relay onto a panel or the like, a socket may be providedbeforehand in the panel so that the terminal ends of the switch contactmembers may be fitted into the corresponding bores in the front face ofthe socket. FIGS. 79 show a mounting member 91 which can be used for thesame purpose. To use the member 91 the casing 12 must be provided on theupper surface of its top wall with a pair of projections 83 and 84 andthe base plate 22 of the switch structure 11 must be provided with agroove 85 (FIGS. 7 and 8). The mounting member 91 comprises a base wall92 and a pair of upper and lower support wall elements 93 and 94extending from the opposite ends of the base Wall 92 substantiallyperpendicularly thereto. The upper support wall 93 is formed with a pairof apertures 95 and 96 for the projections 83 and 84 of the casing 12 toengage in and the lower support wall 94, with a bent edge 97 to engagein the groove 85 of the base plate 22. The mounting member 91 may besecured to the panel 100 by means of a screw 101 passing through a hole97 formed in the wall 92 of the mounting member 91. A support tongue 99is lanced out from the wall 92 to extend in the same direction as theupper and lower support walls 93 and 94 so that when the relay ismounted on the member 91, the outer edge of the tongue 99 abuts againstthe side Wall of the casing 12, thereby preventing the relay from beingmoved toward the panel 100. Another tongue 98 is lanced out from thewall 92 of tfhe mounting member 91 in the opposite direction to that ofthe tongue 99, so that it may be inserted into a corresponding hole 102formed in the panel 100, thereby preventing the rotational movement ofthe mounting member 91 about the screw 101.

To mount the relay onto the panel by means of the mounting member 91,the member 91 is first secured to the panel, and then the bent edge 97of the lower support wall 94 of the member 91 is inserted into thegroove 85 of the base plate 22 of the switch structure 11 and the relayis pushed in between the support walls 93 and 94 as far as theprojecting lugs 83 and 84 on the top wall of the casing 12 engage in theapertures 95 and 96 formed in the upper wall 93 of the mounting member91. To dismount the relay from the mounting member 91, the relay maysimply be pulled to disengage the projections 83 and 84 from theapertures 95 and 96 and then the bent edge 97 from the groove 85.

FIG. shows a modified actuator 51 which can be used in place of theactuator 51 of FIG. 5. The actuator 51' has one side portion bifurcatedto provide a pair of fingers 51a and 51b, and the other side portionsimilarly bifurcated to provide a pair of fingers 51c and 51d. Each pairof fingers bear on the movable contact 45, 45' at two places or pointsthereon, so that even when the actuator is more or less displacedrelative to the movable contact member, the actuator can press evenly onthe movable contact member, thereby assuring even contact pressure ofthe movable contact against the stationary contacts.

The invention has various advantages such as follows: The electromagnetstructure 10 and the switch mechanism 11 are independent of each other,and no screws or the like are required to assemble them, so that tliemanual work involved in assembling them is quite simple and easy. In theswitch mechanism, since the movable contact member actuator 51 or 51' isslidable up and down in the guide grooves 36, 36, no positionalfluctuations of the actuator occurs during its sliding movement, so thatthe movable contact members also move properly, thereby providing a goodcontact pressure on the stationary contacts. The two movable contactmembers 45 and 45' are supported by the separate coil springs 46 and46', respectively, so that it is possible to regulate the contactpressure of each movable contact independently of that of the other. Asthe two contact chambers 27 and 28 are separated by the insulatingpartition Walls and 26, there will be no possibility of the contactsshort-circuiting in the two contact chambers 27 and 28.

What we claim is:

1. An electromagnetic relay comprising: an electromagnet structurecomprising an electromagnetic coil wound on a spool, means for providinga path for the magnetic flux produced by said coil upon energizationthereof, a stationary core disposed in said coil, a plunger adapted tobe attracted toward said stationary core upon energization of said coil,and spring means normally urging said plunger downwardly away from saidcore; a switch structure independent of said electromagnet structure andcomprising a base plate, partition wall means dividing the space abovesaid base plate into at least two contact chambers, guide groove meansextending transversely of said partition wall means, a plurality ofstationaryv contact members disposed in each said chamber, a movablecontact adapted to be brought into and out of contact with saidstationary contacts in each said chamber, a spring for biasing each saidmovable contact member upward, and an actuator slidable in said guidegroove Cal means and engageable with said movable contact member topress the same down against the resiliency of said spring; and a bindingmember mounted on said electromagnet structure and gripping said switchstructure to hold the same in assembled relation so that said plungerbears on said actuator to normally urge said actuator downward.

2. The relay of claim 1, wherein said flux path providing meanscomprises a generally U-shaped yoke enclosing said coil therein and anend plate having notched ends and closing the open end of said yoke,with the ends of the opposite legs of said yoke being fitted into thenotches formed in the opposite ends of said end plate.

3. The relay of claim 1, wherein said actuator acts on said movablecontact members in both said chambers simultaneously.

4. The relay of claim 3, wherein said actuator has each of its oppositeend portions bifurcated to provide a pair of fingers bearing on saidmovable contact member in each said chamber.

5.. The relay of claim 1, wherein said stationary contact members ineach said chamber are disposed one pair at each of the opposite ends ofsaid movable contact member, one of each said pair of stationary contactmembers being disposed above the other, with said movable contact memberbeing interposed therebetween.

The relay of claim 1, wherein each said spring is disposed beneath themiddle portion of each said movable contact member.

7. The relay of claim 1, wherein said binding member comprises agenerally U-shaped frame having a pair of side leg portions andenclosing said assembled electromagnet and switch structures, saidswitch structure having a projection formed. on eachof the oppositelateral side walls thereof for gripping the ends of said side legportions, respectively. b

8. The relay of claim 1, further including a transparent box-like casinghaving a bottom opening and enclosing said assembled electromagnet andswitch structures therein, said casing engaging at its lower end withsaid end plate of said switch structure to hold said assembledstructures therein.

9. The relay of claim 8, in combination with a mounting membercomprising a base wall and a pair of support walls extending from theopposite ends of said base wa l generally perpendicularly thereto, sothat one of said support walls engages the top wall of said casing whilethe other engages said base plate of said switch structure.

References Cited

